1. Field of the Invention
The present invention relates to a zoom lens system and in particular to a zoom lens system suitable for a video camera and an electronic still camera using a solid-state imaging device applicable to a plurality of imaging devices with different image heights.
2. Related Background Art
Recently, in a rapidly spreading field of a digital camera or a video camera, lenses for such camera are required to be compact and have high optical performance as those for general cameras. On the other hand, since imaging devices have various image sizes, the optical system has to be redesigned upon changing the size of the imaging device.
A zoom lens, for example, is ideally designed for a particular image height for a certain imaging device and other image heights of the other imaging devices are not taken into consideration.
In order to solve the problem, Japanese Patent Application Laid-Open No. 2003-121738 proposes that when an imaging device having other image height than designed one is used, it is coped with removing a part of optical elements from the zoom lens.
However, in the example disclosed in the above patent document, when the image height of the imaging device is changed, since the zoom lens copes with removing a part of the zoom lens components, there is a possibility that optical performance become worse for a plurality of imaging devices having different image heights. Moreover, a mechanism for removing a part of optical elements has to be arranged, so that there is a problem that the zoom lens system becomes complicated and large.